The BVM sock is an in tank fuel filter for Chrysler cars from way back, but still maintains a current automotive store pare number, I got it someone in my records.
But what's weird is I have 20 year old jets that have BVM UAT still in them and have had fuel in them all these years with only small discoloring of Nalgene bottle and never an issue with the socks. I have used exclusively all these years Mobil Turbine II oil only ever had AMT and now Xicoy.......